This application relates to a method of milling involute splines. This application claims the filing date of U.S. Provisional Patent Application Ser. No. 60/793,820 filed on Apr. 21, 2006 and titled “Replaceable Insert For Milling Splines” filed in the name of the same inventors herein. The present invention is of the general type disclosed in U.S. Pat. No. 5,112,162 tiled “Thread Mill Cutter Assembly” and issued to the same inventors hereof. Patent '162discloses replaceable inserts having a cutting body that is mounted in a recess formed on the shank of a tool holder. The inserts disclosed herein are also removable and replaceable on a tool holder.